A Silver Studded Summer

Silver-studded blue butterfly amongst grass stalks

It seems that summer has been slow to start, but nature can’t afford to wait and one of Norfolk’s rarest butterflies has taken to the wing pretty much on cue. Silver-studded blue butterflies have one of the most amazing symbiotic lifecycles you could imagine. Frequenting heathland, they plant their eggs on fresh low lying gorse or heather and depend upon just two specific species of black ant, Lasius niger and Lasius alienus to complete their lifecycles.

Silver-studded blue butterfly on ribwort plaintain
Silver-studded blue butterfly on ribwort plaintain

Silver-studded blue butterflies live in small colonies. They are a sedentary species, tending to stay local and fly low to the ground. Unlike the blue males, female studded-blue butterflies are brown in colour, but both share the same silvery blue scales in the black spots on the underside of their hind wing for which the butterfly gets its name.

Adults survive only a few days each summer, just long enough to mate and lay eggs. The caterpillars hatch in spring and are and nurtured by the black ants in exchange for a sugary secretion produced by a special gland. The caterpillar pupates underground in the ants nest before emerging as an adult.

Silver-studded blue butterfly amongst grass stalks
Silver-studded blue butterfly amongst grass stalks